16gb vs 32gb ssd cache + 1tb hdd

I was looking at getting an acer chromebook and installing linux on it and replacing the msata ssd with a larger 128gb one and I was going to put the 16 or 32gb one as a cache for my desktop gaming rig. My question is how much of a difference would there be in reality.

I'm just a little curious, it probably doesn't matter much, most of my time on the computer is chrome related, so I don't really know what else would get cached, I play probably too many different games for them to get loaded to the cache, so for my use case, my guess is there would be negligible difference.

IMO go large

It will be worthwhile for the overall system performance anyway, so have a go at it until you can get a full sized SSD in there too.